1. Field of the Invention
The present invention relates generally to a double shield exterior airbag device with a one-way gas flow structure and, more particularly, to a double shield exterior airbag device which is capable of preventing the outflow of gas caused by the bursting of an overlapping portion in the event of a vehicle collision.
2. Description of Related Art
Generally, a vehicle which is driving on a road is provided with various kinds of safety devices so as to protect a driver and a passenger against an unexpected accident. A representative safety device is an airbag device that directly protects a driver and a passenger sitting in a front seat of the vehicle.
Such an airbag device is an interior airbag device which is inflated inside a vehicle in the event of an accident, thus protecting a passenger who is inside the vehicle. However, the airbag device is problematic in that a vehicle colliding with an external object, an oncoming vehicle, and a person who is outside the vehicle are never protected. It is particularly difficult to safely protect a passenger using only the interior airbag device of the vehicle.
Therefore, as shown in FIG. 6, an exterior airbag system has been developed to reduce the risk of injury to a passenger and damage to a vehicle. The exterior airbag system is constructed so that an exterior airbag A is mounted to a bumper B which is provided on the front of a vehicle, and a radar sensor LS or a camera sensor CS is provided at a position on the vehicle to detect the speed and distance of an external object before a collision, thus transmitting the detected result to a control unit U. That is, if the control unit U expects a collision before a vehicle collides with an external object such as another vehicle, it is determined whether the exterior airbag A is deployed or not. A deployment signal is generated based on the determined result so as to deploy the exterior airbag A, thus mitigating impact force in the event of a vehicle collision.
As shown in FIG. 7, the conventional exterior airbag device includes an airbag cushion 20 and an inflator 30. The airbag cushion 20 is accommodated in an airbag housing 10 which is mounted to a bumper of a vehicle in such a way as to be deployed forwards, and has partitioned chambers 23 which are partitioned by a plurality of internal partitions 25 and are simultaneously supplied with gas at the time of being deployed. The inflator 30 supplies gas to the partitioned chambers 23 so as to provide deploying force to the airbag cushion 20.
However, the conventional exterior airbag device is problematic in that the airbag cushion 20 is made by overlapping five or more pieces of nylon fabric so as to have pressure resistance and heat resistance, so that the multi-layered airbag cushion 20 may incur excessive material costs and manufacturing costs.
Further, the conventional exterior airbag device is problematic in that the partitioned chambers 23 are connected to a single space, so that gas present in the entire airbag cushion is lost if the airbag cushion is damaged by a sharp object during a collision after the airbag cushion has been deployed, and thus it is difficult to maintain base pressure resistance. As a result, the function of the airbag may be undesirably lost.
Furthermore, the conventional exterior airbag device is problematic in that an overlapping portion 26, which connects a cushion material to another cushion material when the airbag cushion 20 is manufactured, is overlapped once and then is sewn by a seam 27, so that the seam 27 of the overlapping portion may be torn in the event of a collision, thus causing the loss of gas present in the entire cushion.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.